Can opener with cutter and feed wheel release means

ABSTRACT

An electrically powered can opener has a detachable cutter base carrying rotatably a circular cutter and having a pivotal shaft, and a base carrying rotatably a feed wheel and a feed wheel holder and having latching members. The fall off of these base and cutter base from a housing is precluded by the engagement between the pivotal shaft in the housing and a locking member operable from outside the housing and by the engagement between the latching members in the housing and the locking member itself or a base locking member operated suitably by this. The cutter base and the base become separable from the housing individually and in this order by pushing in the locking member twice.

United States Patent Yamamoto Dec. 23, 1975 [75] Inventor: Osamu Yamamoto, Nagoya, Japan [73] Assignee: Kabushiki Kaisha Aichidenkikosakusho, Japan 22 Filed: Jan. 30, 1975 [21] Appl. No.: 545,469

[30] Foreign Application Priority Data Mar. 12, 1974 Japan' 49-28242 May 10, 1974 Japan 49-52675 52 US. Cl 30/4 R [51] Int. Cl. B67B 7/38 [58] Field of Search 30/4 R, 8, 8.5, 9, 15,

[56] References Cited UNITED STATES PATENTS 3,689,999 9/1972 Swanke 30/4 R 3,757,416 9/1973 Yamamoto 30/4 R 3,798,764 3/1974 Yamamoto 30/4 R Primary ExaminerJames L. Jones, Jr. Assistant Examiner-Gary L. Smith Attorney, Agent, or Firm-William Anthony Drucker [57] ABSTRACT An electrically powered can opener has a detachable cutter base carrying rotatably a circular cutter and having a pivotal" shaft, and a base carrying rotatably a feed wheel and a feed wheel holder and having latching members. The fall off of these base and cutter base from a housing is precluded by the engagement between the pivotal shaft in the housing and a locking member operable from outside the housing and by the engagement between the latching members in the housing and the locking member itself or a base locking memberoperated suitably by this. The cutter base and the base become separable from the housing individually and in this order by pushing in the locking member twice.

l0Claiins, 17 Drawing Figures US. Patent 1366.23, 1975 51161311015 3,927,472

US. Patent Dec.23, 1975 Sheet 2 of5 3,927,472

15 FIG.3 1 2,8 47 52 5s Sheet 3 of 5 3,927,472

US; Patent Dec. 23, 1975 CAN OPENER WITH CUTTER AND FEED WHEEL RELEASE MEANS BACKGROUND OF THE INVENTION This invention relates to an electrically powered can opener in which the end rim of a can is inserted between a feed wheel extending rotatably in front of the upright front member of the housing and a circular cutter carried by the cutter base pivotally supported on the housing above the feed wheel and the lid of the can is cut progressively near the inside surface of theend rim. Mainly for the purpose of cleaning the cutter after acan opening operation, the electrically powered can opener of this type is constructedin a manner that the cutter together with the cutter base can be separated from the housing. However in the course of-repeated usages of the can opener, it happens that notonly the cutter base but also the feed wheel generally affixed to the end extremity of the driving shaft extending from the. interior to the exterior of the housing is necessary to be washed. Not only because the feed wheel is considerably small but also because it engages complicatedly with driving mechanisms and bearings, it is considerably difficut to detach only this feed wheel readily from the housing. The removal of the feed wheel together with driving mechanisms is not favourable because it results in the contamination of the feed wheel with the oil of driving mechanisms and the like at the time of washing. Besides, because of much more chances of washing cutters than those of washing the feed wheel, the cutter should be first detached from and attached to the housing repeatedly readily and independently of the feed wheel. Then, the detachment and mounting of the feed wheel should be possible, too, as occasion demands. The object of the present invention is to provide anelectrically powered can openerin which only thecutter can be detached by a first operation and then also the feed wheel can be removed by a second operation done as occasion demands.

SUMMARY OF THE INVENTION An electrically powered can opener according to the present invention includes a base having latching members and mountable detachably on the front member of a housing and a cutter base carrying a circular cutter rotatably and provided with a pivotal shaft, the pivotal shaft being inserted in the housing through a loose aperture of the housing and the latching members being inserted in the housing through slots of the housingfThe can opener includes further a locking member which is movable up and down in the housing and engageable with the pivotal shaft to preclude the fall off of the cutter base at least and a base locking member movable vertically which can be operated by the locking member in some cases and be engageable with the latching members in the housing to preclude the fall off of the base. A feed wheel holder carrying a feed wheel is supported rotatably in the base and is connected to the end extremity of a driving shaft projecting forwards through the front member of the housing so that both are separable from each other in the axial direction of the driving shaft. When the pivotal shaft is held in the front member and is locked by the locking member not to fall off, the feed wheel is connected to the driving shaft and is in position to be rotated by the same. When the base locking member is not employed, the cutter base becomes detachable first by depressing down the locking member by a certain length and then also the base becomes so by depressing down the locking member again. When the base locking member is employed, the locking member is returned once after the disengagement of it with the pivotal shaft and then depressed again. Thus, the base locking member is operated by the locking member and the disengagement between the latching members and the base locking member is established to make the base detachable.

The salient relationships of the present invention have been described. This cutter base according to the present invention can be detached easily together with the cutter, independently of te base including the feed wheel and before the removal of the base. Thus, only the cutter to be washed frequently and the cutter base can be washed easily. When it is necessary to wash also the feed wheel, it becomes detachable by operating the locking member further and can be washed independently of the cutter. The operations to remove the cutter base and the base are hardly mistaken for each other especially when the removal of the base is done by repeated depressions of the locking member.

I IN THE DRAWINGS FIG. 1 is a front elevational view of an electrically powered can opener as a first embodiment,

FIG. 2.is a sectional side elevational view of the electrically powered can opener,

FIG. 3 is a rear view of the electrically powered can opener with the rear member of its housing being taken away,

FIG. 4 is a perspective view in partial cross-section showing-the mounting relationship of a cutter base and a base with respect to the housing,

FIG. 5 is a rear view of the cutter base and the base,

FIG. 6 is a section along line 66 in FIG. 3,

FIG. 7 is a side elevational view of the base separated from the housing,

FIG. 8 is an exploded perspective view showing the relationship among the housing, the base and the cutter base of the can opener,

FIG- 9a, 9b, and 9c are a fragmental perspective views showing the connecting relationship between a feed wheel and the driving shaft thereof,

FIG. I0 is a rear view of an electrically powered can opener as a second embodiment with the rear member of its housing being taken away,

FIG. 11 is a view similar to FIG. 2 of the electrically powered can opener of the second embodiment,

FIG. 12 is a fragmental view in partial cross-section showing the mounting relationship of the cutter and the cutter base of the second embodiment, and

FIGS. 13a, 13b, and 3c are a fragmental views in section to explain the operations of the locking member and the base locking member of the second embodiment.

Referring to the drawings, a housing of a can opener is indicated by numeral 10 and is provided with a front member 10'. The front member 10' is so shaped to have a square depressed portion 11, from the internal surface of which a horizontal bearing boss 12 is protruding towards the interior of the housing. On the left of and above the bearing boss 12, another bearing boss 13 is similarly extending towards the interior of the housing from the internal surface of the front member 10' and under the bearing boss 12, a can guide 14 is extending forwardly of the housing 10 from the front member 10'. A cutter base 15 having an integral grip 15 at one end extremity and a pivotal hole 15" at the other end portion is mounted pivotally on the front member by a pivotal shaft 16 inserted in the pivotal hole and the bearing boss 13 and with the end portion of the pivotal shaft 16 a nut 17 is in threaded connection to pivot the cutter base 15 rotatably on the front member 10'. The internal end of the pivotal shaft 16 is pointed and a circular groove 18 is provided near this pointed inner end 16'. The unification of the cutter base 15 and the pivotal shaft 16 is obtained by the nut 17 and another nut 19. From the cutter base 15, a cutter carrying stud 20 is extending in an oblique downward direction and a circular cutter 21 is mounted rotatably on the stud 20, the withdrawal of the cutter being prevented by a screw 22 affixed to the end extremity of the stud 20. As a means for holding a cut off can lid, a magnet 23 is held forwardly of the cutter 21 by an arm 24 extending from the upper portion of the cutter base 15. A base 25, which has such a size that it can be positioned on the front surface of the depressed portion 11, is provided with a pair of latching members 26 extending perpendicularly at both sides of the base. These latching members are inserted in the housing through slots 11' made in the front member 10'. The end portions of these latching members are made thin as shown and the lower edges of the same have cuts 26 and 26' respectively. Through the upper portion of the base 25, a loose aperture 27 is bored, in which the pivotal shaft l6is adapted rotatably and loosely. A push out spring 28 is secured on the front surface of the depressed portion 11 whereby the base placed closely before the front surface of the depressed portion 11 is biased forwardly of the housing by the push out spring 28.

Next, a can driving mechanism is described. In another aperture 29 bored through the base 25, a feed wheel holder 31 carrying feed wheel is inserted for free rotation and the end extremity of the feed wheel holder facing the front surface of the depressed portion 11 is provided with a diametrical jointing groove 32. Along the axis of the feed wheel holder 31, an axial hole 33 is bored for the purpose of faciliating centering between the feed wheel holder and a driving means thereof. The feed wheel holder 31 adapted in the aperture 29 is made considerably thin as compared with the diameter of the aperture 29 and the base 25 is not subjected to a reaction force of the can cutting operation even when the feed wheel 30 is driven. Thus, the can opener suffers from no difficulties in normal operations without provision of lubrication oil to the peripheral portion of the aperture 29. Numeral 34 indicates a circular groove formed on the feed wheel holder 31 and a C-shaped ring 35 of an external diameter larger than the diameter of the aperture 29 is set in said groove in order to preclude the withdrawal of the feed wheel holder. With the base 25 and the cutter base 15 both mounted on the front member 10, the lowermost edge of the cutter 21 is placed closely in front of the uppermost edge of the feed wheel 30. A driving shaft 36 for the feed wheel 30 is inserted rotatably in the bearing boss 12 and a centering member 37 integral and coaxial with the driving shaft 36 is provided on the end portion of the shaft 36 near the depressed portion 11. The centering member has such a form that it can be fit closely in the axial hole 33 but can slide axially. An integral projection 38 of a form suitable for adaption in the jointing groove 32 is formed on the neck portion between the centering member 37 and the driving shaft 36. Accordingly, the centering of the feed wheel holder 31 is maintained by the centering member 37 inserted in the axial hole 33 and the loading force due to can opening operation exerting on the axial hole 33 is born by the centering member, but does not exert on the base 25 as the result of the support of the feed wheel by the centering member 37. Thus, any provision of lubricating oil is not necessary between the feed wheel holder 31 and the base 25. The engagement between the projection 38 and the base 25 makes possible the transfer of the torque from the driving shaft 36 to the feed wheel holder. On the other end portion of the driving shaft 36 extending beyond the end extremity of the bearing boss 12, a gear 39 is fastened by means of a nut 40 and a planar spring 41 is secured on the housing 10 for the purpose of urging the end extremity 36' of the driving shaft 36 further extending beyond the gear 39 towards the front member 10. An electric motor 42 is mounted fixedly in the housing 10 and is connected to the gear 39 through a reduction gear assembly 43. Next, as illustrated in FIGS. 3 and 6, a guiding member 44 of a L-shaped section is secured on the internal surface of the front member 10' under the bearing boss 13 and a pair of guiding apertures 44 and 44 are bored through the horizontal portion of the guiding member 44. A locking member 45 has, at its lower portion, a pair of legs 46 and 46 of a form suitable for being inserted slidably in the guiding aperture and, at its upper portion, an elongate hole 47. The legs 46 and 46 are inserted in the guiding apertures 44' and 44 and positioned near the internal surface of the front 'member 10' by means of a screw 48 screwed into the front member 10' whereby the vertical position of the locking member 45 is adjustable within the length of the elongate hole 47. A compression spring 50 placed between a spring mount 49 and the bearing boss 12 biases the locking member 45 upwardly. The locking member 45 is provided with a pair of rectangular openings 51 and 51 where latching members 26 and 26 are inserted and the cuts 26 and 26' receive the lower edges of the openings 51 and 51. A push button 52 is attached fixedly on the top of the locking member 45 and extends ordinarily through the top member of the housing 10 upwardly. A start push button 53 is extending upwardly of the top member of the housing at a position where the push button 53 can be depressed by the grip 15' of the cutter base 15 and electrical contacts 55 and 55' connected in the power source circuit of the electric motor 42 are operated by an operation rod 54 connected to the push button 53. Another elongate hole 56 is bored through the locking member 45 near the elongate hole 47 and the pointed end 16' of the pivotal shaft 16 is extending through this elongate hole 56. When the locking member 45 is held upward by the force of the compression spring 50, the locking member 45 engages with the circular groove 18 of the pivotal shaft 16 at the elongate hole 56 and the pivotal shaft 16 and therefore'the cutter base 15 are held not to fall off from the housing 10. A push spring 16" is urging the pointed end 16' of the pivotal shaft 16 I towards the front member 10'. The depth of the biting engagement between the legs 46 and the cuts 26' is determined to be larger than that between the locking member 45 and the circular groove 18 and thus the disengagement between the locking member 45 and the circular groove 18 is established by pushing the push button 52 by a first step length and then the disengagement between the legs 46 and the cuts 26' is attained by pushing the push button further by a second step longer length.

Next, the treatment of the above-mentioned construction is described. As shown in FIG. 4, the cutter base 25 and the base unified with the pivotal shaft 16 are mounted on the housing 10. In this case, the latching members 26 and 26 inserted in the slots 11' and 11 respectively and then the base is pushed towards the front member. As the thin end portion of the latching member 26 begins to enter the square opening 51, the end portion lowers the locking member 45 against the spring 50. At the same time, the centering member 37 for the driving shaft 36 begins to enter the axial hole 33 of the feed wheel holder 31. In the course of these operations, the cuts 26 come in registration with the lower edges of the openings 51 and the locking member 45 is returned by a length equal to the depth of the cut 26, thus the base 25 being mounted on the housing 10. If thejointing groove 32 of the feed wheel holder 31 coincides with the projection 38 of the driving shaft 36 by chance, the fit situation as shown in FIG. 90 results. However, the jointing groove 32 does not coincide with the projection 38 but contacts with the same in a crossing position ingene ral as shown in FIG. 9b. The increase in the axialdistance due to the misfitting between the jointing groove 32 and the projection 38 is adjusted by the axial displacement of the driving shaft 36 against planar spring 41 and the driving shaft 36 is biased by the spring 41. Next, the pivotal shaft 16 is inserted in the bearing boss 13 and the pointed end 16 is pushed in the elongate hole 56. In this stage, the locking member 45 is lowered once by the disengage length equal to the depth of the circular groove 18 but the disengagement between the legs 46 and the cuts 26' does not result because the depth of the cut 26 is larger than this disengage length according to the construction of the can opener. After the engagement of the locking member 45 with the circular groove 18 in the elongate hole 56,the locking member 45 is returned to its uppermost position and the cutter base 15 becomes mounted on the housing 10. With the cutter base 15 andthe base 25 thus mounted, the lower portion of the end rim of a can to be opened is made in contact with the feed wheel 30. When the grip 15 of the cutter base 15 is gasped to be lowered, the start push button 53 is depressed by the grip 15' to close the electrical contacts 55 and 55' and the electric motor 42 is started to rotate the driving shaft 36 through the reduction gear assembly 43. The feed wheel 30 is rotated with'support by the driving shaft 36 immediately when the projection 38 is fit in the jointing groove 32 and after only the driving shaft 36 rotates to fit projection 38 in the jointing groove 32 due to the biasing force of the planar spring 41 when the projection is not fit in the jointing groove 32. At this time, as the edge of the circular cutter 21 is in contact with the can lid closely inside the end rim and the can is rotated by the feed wheel 30, also the circular cutter 21 is rotated with the stud 20 as the center axis. At the same time, the driving force of the feed wheel 30 exerting on the circular cutter 21 through the can lid rotates the cutter base 15, as a torque, in a direction towards the can around the pivotal shaft 16, the piercing position of the circular cutter 21 into the can lid being maintained automatically. In this situation, the circular cutter 21 proceeds to open the can. When the can is cut out completely, the above-mentioned torque disappears and the grip 15 is lifted slightly by a restoring spring suitably provided. Then the electrical contacts and 55' are disconnected to stop the electric motor 42. The opened can can be withdrawn from the can opener by further lifting the grip 15'.

Next, when it is desired to withdraw only the circular cutter 21 or both the circular cutter 21 and the feed wheel 30 from the housing for the purpose of washing the push button 52 is pushed down by a short distance to lower the locking member 45 once. As the result, the engagement between the locking member 45 and the circular groove 18 is released, the pivotal shaft 16 is pushed out towards the front member 10' and the cutter base becomes detachable from the housing 10. Further, by pushing down the push button 52 deeper, the cut 26' is made to become out of registration with the lower edge of square opening 51 and. the engagement between the locking member 45 and vthe latching member 26 is released. Because no members prevent the base 25 from-moving forwardly of the housing 10, the base 25 is pushed forth slightly by. the force of the push out spring 28 or the force of the planar spring 41 in the absence of the push out spring 28 urging the base 25 forwardly and keeps its slightly pushed out position. Then, the cutter base 15 carrying the circular cutter 21 and the base 25 carrying the feed wheel 30 are withdrawnfrom the housing 10, the situation shown in FIG. 8 being attained. When it is desired to detach only the cutter base 15, the base 25 can remain mounted on the housing 10 if the push button 52 is left free after it has been pushed down by the short first steplength.

Next, referring to FIGS. 10-13, another embodiment is. described. Those members in this embodiment which are same as or similar with members in the previous embodiment are given the same reference numerals as corresponding ones in the first embodiment and the constructional description of these members is omitted. A base locking member 57 is provided at its lower-end with legs 58 and 58 being adapted to inserted slidably in the guiding apertures 44' and its upper portion is made in a planar spring form so that it can urge a locking member 62 to be described later. The legs 58 are inserted ordinarily in the guiding apertures 44. A compression spring 59 is inserted compressingly between a spring seat 60 provided on the base locking member 57 and the guiding member 44, and biases the base locking member 57 always upwards. The upper edge 57' of the base locking member 57 is adapted to be in biting engagement with cuts 26. Another guiding member 61 of L-shaped cross-section is secured on the internal surface of the front member 10 under the bearing boss 13 and a guiding aperture 61 is bored through the horizontal portion of the guiding member 61. A locking member 62 is provided, at it lower portion, with a leg 63 adapted to be inserted slidably in the guiding aperture 61 and this leg is inserted in the guiding aperture 61'. A compression spring 64 for biasing the locking member 62 upwards-is provided around the locking member 62. An elongate hole 65 is bored through the upper portion of the locking member 62, and the pointed end 16' of the pivotal shaft 16 is projecting through this elongate hole. When the locking member 62 is held upwards by the force of the compression spring 64, the locking member 62 engages with the circular groove 18 of the pivotal shaft 16 at this elongate hole to preclude the fall off of the pivotal,

shaft 16 and therefore the cutter base 15 from the housing 10. In this case, the pointed end 16' of the pivotal shaft 16 pushes the base locking member 57 so as to separate the same from the locking member 57 and the pivotal shaft 16 itself is adapted to be biased towards the front member A base tripping member 66 is provided protrudingly on the locking member 62. This base tripping member 66 is adapted to be positioned over the top of the base locking member 57 when the locking member 62 is retired upwards and the base locking member 57 is not separated from the locking member 62 by the pointed end 16 of the pivotal shaft 16 and to set the base locking member forth 57 as the locking member 62 proceeds to move downwards. Of course, the base tripping member 66 does not engage with the base locking member 57 when the base locking member 57 is pushed by the pointed end of the pivotal shaft 16.

Next, description is taken on that portion of the treatment of the can opener as the second embodiment which differs from that of the previous embodiment. After the mounting of the base on the housing 10, the pivotal shaft 16 is inserted in the bearing boss 13 and the pointed end 16 is pushed in the elongate hole 65. Thus, the cutter base 15 is mounted on the housing 10 and at the same time, the upper portion of the base locking member 57 is separated from the locking member 62 by the pointed end 16'.

When it is desired for the purpose of washing to withdraw only the cutter 21 or both the cutter 21 and the feed wheel from the housing, the push button 52 is depressed firstly to lower the locking member 62 once. As the result, the engagement between the circular groove 18 and the locking member 62 at the elongate hole 65 is released as is seen in FIG. 13a, the pivotal shaft 16 is pushed out forward towards the front member 10' by the force of the base locking member 57 as is shown in FIG. 13b and the cutter base 15 becomes detachable from the housing 10. Then, by releasing the push button 52 once to cause the locking member 62 to retire upwards, the base locking member 57 becomes free from being biased towards the locking member 62 by the pivotal shaft 16 and consequently the upper end of the base locking member 57 comes right under the base tripping member 66 as shown in FIG. 130. If the push button 52 is pushed again at this stage, the base locking member 57 together with locking member 62 goes downwards and this downward movement results in the disengagement between the cuts 26' and the upper edges 57' and in the disengagement between the base locking member 57 and the latching members 26. The base 25 projects forwards slightly as in the case of the previous embodiment because no members prevent the base from going forth and the base maintains its situation just resulted. When it is suffice to remove only the cutter base 15, the push button 52 is released to be returned upwards after it is operated only once and the base 25 is left mounted on the housing 10.

What I claim is:

1. In an electrically powered can opener having a housing, a driving shaft rotatably supported in said housing and an electric motor for rotating said driving shaft, a combination therewith of a front member of said housing, a cutter base having a grip at one end portion, a circular cutter rotatably carried by said cut ter base, a pivotal shaft attached to said cutter base at its one end, said pivotal shaft being inserted rotatably through said front member so as to position said cutter base right before said front member, a base closely mounted on said front member and provided with an aperture, a feed wheel holder inserted loosely in said aperture. a feed wheel carried rotatably by said feed wheel holder, latching members secured vertically on said base, said latching members extending in the interior of said housing through slots bored through said front member, said feed wheel holder and said driving shaft being connected so that rotation may be transmitted from the latter to the former and both may be separable axially from each other, a locking member operable from the exterior of said housing and movable vertically, said locking member having such a form that at a certain position thereof it cooperates with said pivotal shaft and said latching members to preclude the separation of said cutter base and said base from said front member, a spring for biasing said locking member to a position where said locking member engages with said pivotal shaft and said latching members, the engagement between said locking member and said pivotal shaft being released by depressing said locking member against said spring by a certain distance and the engagement between said locking member and said latching member being released by depressing said locking member against said spring by a larger distance.

2. The combination as described in claim 1 including a pointed end of said pivotal shaft, a circular groove formed on said pivotal shaft near said pointed end, an elongate hole bored through said locking member, a biasing member mounted on said housing for urging said pointed end towards said housing, the fall off of said cutter base from said front member being precluded by the engagement between said circular groove and said elongate hole, cuts formed at the lower edges of said latching member and openings bored through said locking member, the fall off of said base from said front member being precluded by the engagement be tween said cuts and the edges of said openings.

3. The combination as described in claim 1 including an axial hole bored along the axis of said feed wheel holder, a diametricaljointing groove formed on the end surface of the feed wheel holder facing said driving shaft, an integral centering member fromed on the end portion of said driving shaft facing said feed wheel holder, a projection formed on the neck portion between said driving shaft and said centering member, said centering member having a form fit closely in said axial hole, said projection having a form fit closely in said diametrical jointing groove, and a spring secured on said housing for biasing said driving shaft towards said front member.

4. The combination as described in claim 1 including a spring mounted on said front member, said spring biasing said base in the direction to separate it from said housing.

5. The combination as described in claim 1 including electrical contacts connected in the power source circuit of said dlectrical motor, an operation rod for operating said contacts and a start push button attached to said operation rod, said start push button extending exteriorly of the top of said housing at a position where said start push button can be depressed by said grip of said cutter basev 6. In an electrically powered can opener having a housing, a driving shaft rotatably supported in said housing and an electric motor for rotating said driving shaft, a combination therewith of a front member, a cutter base having a grip at one end portion, a circular cutter rotatably carried by said cutter base, a pivotal shaft attached to said cutter base at its one end, said pivotal shaft being inserted rotatably through said front member so as to position said cutter base right before said front member, a base closely mounted on said front member and provided with an aperture, a feed wheel holder inserted loosely in said aperture, a feed wheel carried rotatably by said feed wheel holder, latching members secured vertically on said base, said latching members extending in the interior of said housing through slots bored through said front member, said feed wheel holder and said driving shaft being connected so that rotation may be transmitted from the latter to the former and both may be separable axially from each other, a locking member operable from the exterior of said housing and movable vertically, said locking member having such a form that at a certain position thereof it cooperates with said pivotal shaft to preclude the separation of said cutter base from said front member, a spring for biasing said locking member to a position where said locking member engages with said pivotal shaft, the engagement between said locking member and said pivotal shaft being released by depressing said locking member against said spring, a base locking member movable vertically and adapted to be operated by said locking member not engaging with said pivotal shaft, said base locking member having such a form that at a certain position thereof it cooperates with said latching members to preclude the separation of said base from said front member, and a second spring for biasing said base locking member to a position where said base locking member engages with said latching member, the engagement between said base locking member and said latching members being released by depressing said locking member, which is not engaging with said pivotal shaft, against said second spring.

7. The combination as described in claim 6 including a pointed end of said pivotal shaft, a circular groove formed on said pivotal shaft near said pointed end, an elongate hole bored through said locking member, a biasing member mounted on said housing for urging said pointed end towards said housing, the fall off of said cutter base from said front member being precluded by the engagement between said circular groove and said elongate hole, such an upper portion of said base locking member that is formed as a planar spring pushing against said locking member, cuts formed at the lower edges of said latching members, an upper edge for engagement formed on said base locking member, a base tripping member attached to said locking member, the fall off of said base from said front member being precluded by the engagement between said cuts and said upper edge for engagement, said base locking member being adapted to be separated from said locking member by said pointed end of the pivotal shaft in engaging relationship with said locking member but being operable by said base tripping member when said engaging relationship is released.

8. The combination as described in claim 6 including an axial hole bored along the axis of said feed wheel holder, a diametricaljointing groove formed on the end surface of the feed wheel holder facing said driving shaft, an integral centering member formed on the end portion of said driving shaft facing said feeding wheel holder, a projection formed on the neck portion between said driving shaft and said centering member, said centering member having a form fit closely in said axial hole, said projection having a form fit closely in said diametrical jointing groove, and a spring secured on said housing for biasing said driving shaft towards said front member.

9. The combination as described in claim 6 including a spring mounted on said front member, said spring biasing said base in the direction to separate it from said housing.

10. The combination as described in claim 6 including electrical contacts connected in the power source circuit of said electric motor, an operation rod for operating said contacts and a start push button attached to said operation rod, said start push button extending exteriorly of the top of said housing at a position where said start push button can be depressed by said grip of said cutter base. 

1. In an electrically powered can opener having a housing, a driving shaft rotatably supported in said housing and an electric motor for rotating said driving shaft, a combination therewith of a front member of said housing, a cutter base having a grip at one end portion, a circular cutter rotatably carried by said cutter base, a pivotal shaft attached to said cutter base at its one end, said pivotal shaft being inserted rotatably through said front member so as to position said cutter base right before said front member, a base closely mounted on said front member and provided with an aperture, a feed wheel holder inserted loosely in said aperture, a feed wheel carried rotatably by said feed wheel holder, latching members secured vertically on said base, said latching members extending in the interior of said housing through slots bored through said front member, said feed wheel holder and said driving shaft being connected so that rotation may be transmitted from the latter to the former and both may be separable axially from each other, a locking member operable from the exterior of said housing and movable vertically, said locking member having such a form that at a certain position thereof it cooperates with said pivotal shaft and said latching members to preclude the separation of said cutter base and said base from said front member, a spring for biasing said locking member to a position where said locking member engages with said pivotal shaft and said latching members, the engagement between said locking member and said pivotal shaft being released by depressing said locking member against said spring by a certain distance and the engagement between said locking member and said latching member being released by depressing said locking member against said spring by a larger distance.
 2. The combination as described in claim 1 including a pointed end of said pivotal shaft, a circular groove formed on said pivotal shaft near said pointed end, an elongate hole bored through said locking member, a biasing member mounted on said housing for urging said pointed end towards said housing, the fall off of said cutter base from said front member being precluded by the engagement between said circular groove and said elongate hole, cuts formed at the lower edges of said latching member and openings bored through Said locking member, the fall off of said base from said front member being precluded by the engagement between said cuts and the edges of said openings.
 3. The combination as described in claim 1 including an axial hole bored along the axis of said feed wheel holder, a diametrical jointing groove formed on the end surface of the feed wheel holder facing said driving shaft, an integral centering member fromed on the end portion of said driving shaft facing said feed wheel holder, a projection formed on the neck portion between said driving shaft and said centering member, said centering member having a form fit closely in said axial hole, said projection having a form fit closely in said diametrical jointing groove, and a spring secured on said housing for biasing said driving shaft towards said front member.
 4. The combination as described in claim 1 including a spring mounted on said front member, said spring biasing said base in the direction to separate it from said housing.
 5. The combination as described in claim 1 including electrical contacts connected in the power source circuit of said dlectrical motor, an operation rod for operating said contacts and a start push button attached to said operation rod, said start push button extending exteriorly of the top of said housing at a position where said start push button can be depressed by said grip of said cutter base.
 6. In an electrically powered can opener having a housing, a driving shaft rotatably supported in said housing and an electric motor for rotating said driving shaft, a combination therewith of a front member, a cutter base having a grip at one end portion, a circular cutter rotatably carried by said cutter base, a pivotal shaft attached to said cutter base at its one end, said pivotal shaft being inserted rotatably through said front member so as to position said cutter base right before said front member, a base closely mounted on said front member and provided with an aperture, a feed wheel holder inserted loosely in said aperture, a feed wheel carried rotatably by said feed wheel holder, latching members secured vertically on said base, said latching members extending in the interior of said housing through slots bored through said front member, said feed wheel holder and said driving shaft being connected so that rotation may be transmitted from the latter to the former and both may be separable axially from each other, a locking member operable from the exterior of said housing and movable vertically, said locking member having such a form that at a certain position thereof it cooperates with said pivotal shaft to preclude the separation of said cutter base from said front member, a spring for biasing said locking member to a position where said locking member engages with said pivotal shaft, the engagement between said locking member and said pivotal shaft being released by depressing said locking member against said spring, a base locking member movable vertically and adapted to be operated by said locking member not engaging with said pivotal shaft, said base locking member having such a form that at a certain position thereof it cooperates with said latching members to preclude the separation of said base from said front member, and a second spring for biasing said base locking member to a position where said base locking member engages with said latching member, the engagement between said base locking member and said latching members being released by depressing said locking member, which is not engaging with said pivotal shaft, against said second spring.
 7. The combination as described in claim 6 including a pointed end of said pivotal shaft, a circular groove formed on said pivotal shaft near said pointed end, an elongate hole bored through said locking member, a biasing member mounted on said housing for urging said pointed end towards said housing, the fall off of said cutter base from said front member being precluded by the engagement between said circular groove and said elongatE hole, such an upper portion of said base locking member that is formed as a planar spring pushing against said locking member, cuts formed at the lower edges of said latching members, an upper edge for engagement formed on said base locking member, a base tripping member attached to said locking member, the fall off of said base from said front member being precluded by the engagement between said cuts and said upper edge for engagement, said base locking member being adapted to be separated from said locking member by said pointed end of the pivotal shaft in engaging relationship with said locking member but being operable by said base tripping member when said engaging relationship is released.
 8. The combination as described in claim 6 including an axial hole bored along the axis of said feed wheel holder, a diametrical jointing groove formed on the end surface of the feed wheel holder facing said driving shaft, an integral centering member formed on the end portion of said driving shaft facing said feeding wheel holder, a projection formed on the neck portion between said driving shaft and said centering member, said centering member having a form fit closely in said axial hole, said projection having a form fit closely in said diametrical jointing groove, and a spring secured on said housing for biasing said driving shaft towards said front member.
 9. The combination as described in claim 6 including a spring mounted on said front member, said spring biasing said base in the direction to separate it from said housing.
 10. The combination as described in claim 6 including electrical contacts connected in the power source circuit of said electric motor, an operation rod for operating said contacts and a start push button attached to said operation rod, said start push button extending exteriorly of the top of said housing at a position where said start push button can be depressed by said grip of said cutter base. 